1. Field of Invention
The present invention relates to a lighter, and more particularly to a safety lighter, which comprises a safety arrangement to sealedly mount the supporting frame to the casing for sealedly retaining the liquefied gas therein so as to prevent not only the leakage of the liquefied gas but also the explosive damages of the lighter due to the temperature and the external pressure.
2. Description of Related Arts
Modern butane lighters, such as flint-type lighters or piezoelectric lighters, have become very popular since the lighters are economy, cheap, and easy operation. As shown in FIG. 1, a conventional butane lighter comprises a casing having a liquefied gas chamber, a supporting frame sealedly supported on the casing, a gas emitting nozzle sealedly mounted on the supporting frame to communicate with the liquefied gas chamber, and an ignition device mounted on the supporting frame to generate a spark for ignition. However, such conventional butane lighter has several drawbacks.
In order to seal the supporting frame on the casing, the supporting frame has a sealing edge to seal with an inner surface of the casing to form a sealing line L so as to retain the liquefied gas within the liquefied gas chamber. However, the sealing line L may be broken since the liquefied gas within the casing is sensitive to the temperature, external pressure, and impact. In other words, when any portion of the sealing line L is broken, the liquefied gas may leak or even be vaporized and exploded. For example, when the butane lighter is placed on the dashboard of the vehicle which is parked outdoors, the sunlight will heat up the liquefied gas to vaporize that largely increases the gas pressure in the gas chamber. Generally, the casing is made to withstand the temperature of the liquefied gas below 55°.
In addition, when the liquefied gas is released to the gas emitting nozzle, the impulsive pressure by the phase change of the liquefied gas from liquid to gas is substantially applied to the supporting frame. The impulsive pressure of the liquefied gas substantially pushes the supporting frame upwardly so as to break the sealing line L between the supporting frame and the casing.
Furthermore, the butane lighter further comprises a sealing ring R mounted around the gas emitting nozzle to sealedly mount the gas emitting nozzle on the supporting frame so as to prevent the liquefied gas from leaking through the gap between the gas emitting nozzle and the supporting frame. However, in order to keep the butane lighter in low cost, a common the sealing ring R may be used that the liquefied gas may start leaking after using a period of time. Of course, a very good quality and expensive sealing ring R can be used to extend the service life of the butane lighter but the cost and precise installation of the sealing ring R will largely increase the manufacturing cost of the butane lighter.